diff --git a/exercises/B-hello-world/README.md b/exercises/B-hello-world/README.md
index 27282c4af..c524b7999 100644
--- a/exercises/B-hello-world/README.md
+++ b/exercises/B-hello-world/README.md
@@ -15,4 +15,4 @@ Inside of `exercise.js` there's a line of code that will print "Hello world!".
 - Try to `console.log()` something different. For example, 'Hello World. I just started learning JavaScript!'.
 - Try to console.log() several things at once.
 - What happens when you get rid of the quote marks?
-- What happens when you console.log() just a number without quotes?
+- What happens when you console.log() just a number without quotes? 
diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..5b8268426 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,4 @@
 console.log("Hello world");
+console.log("Nishka Kisten");
+console.log(23);
+
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..adf0353c3 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,6 @@
 // Start by creating a variable `greeting`
-
+var greeting = "Hello World!!!"
+console.log(greeting);
 console.log(greeting);
+console.log(greeting);
+
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..9a78510f5 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+var message = "This is a string";
+var messageType = typeof message;
 console.log(message);
+console.log(messageType);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..5c38de7ae 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+var greetingStart ="Hello, my name is ";
+var name = "Daniel";
+var message= greetingStart + name;
 console.log(message);
diff --git a/exercises/F-strings-methods/README.md b/exercises/F-strings-methods/README.md
index fb07ec8ef..13a75d2c7 100644
--- a/exercises/F-strings-methods/README.md
+++ b/exercises/F-strings-methods/README.md
@@ -2,7 +2,7 @@ You can find out how many characters there are in a string by using the `length`
 
 ```js
 var name = "Daniel";
-var nameLength = name.length;
+ var nameLength = name.length;
 
 console.log(nameLength); // Logs 6
 ```
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..b972879b1 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+var name= "Nishka";
+var nameLength = name.length;
+var message = "My name is " + name + " and my name is " + nameLength + " characters long";
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..e54378493 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,5 @@
 const name = " Daniel  ";
-
-console.log(message);
+var nameLength = name.length;
+var message = "My name is" + name +" and my name is " + nameLength + " characters long";
+var messageTrim = message.trim();
+console.log(messageTrim);
diff --git a/exercises/G-numbers/README.md b/exercises/G-numbers/README.md
index 76a79dab2..75136adf1 100644
--- a/exercises/G-numbers/README.md
+++ b/exercises/G-numbers/README.md
@@ -6,7 +6,7 @@ Unlike strings, numbers do not need to be wrapped in quotes.
 var age = 30;
 ```
 
-You can use mathematical operators to caclulate numbers:
+You can use mathematical operators to calculate numbers:
 
 ```js
 var sum = 10 + 2; // 12
@@ -25,5 +25,5 @@ var difference = 10 - 2; // 8
 ```
 Number of students: 15
 Number of mentors: 8
-Total numnber of students and mentors: 23
+Total number of students and mentors: 23
 ```
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..a227092c2 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,12 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 15;
+var numberOfMentors = 8;
+var studentsAndMentors = numberOfStudents + numberOfMentors;
+
+var messageStudents = "Number of students: " + numberOfStudents;
+var messageMentors = "Number of mentors: " + numberOfMentors;
+var messageBoth = "Total number of students and mentors: " + studentsAndMentors;
+
+console.log(messageStudents);
+console.log(messageMentors);
+console.log(messageBoth);
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..e47e8da98 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,15 @@
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var numberOfBoth = numberOfStudents + numberOfMentors;
+
+var percentageOfStudents = (numberOfStudents / numberOfBoth)* 100;
+var percentageOfMentors = (numberOfMentors / numberOfBoth)* 100;
+
+var percentageRoundStudents =  Math.round(percentageOfStudents);
+var percentageRoundMentors =  Math.round(percentageOfMentors);
+var messageStudents = "Percentage students: " + percentageRoundStudents +"%";
+var messageMentors = "Percentage mentors: " + percentageRoundMentors +"%";
+
+console.log(messageStudents);
+console.log(messageMentors);
+
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..6970717b3 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,7 @@
 function halve(number) {
-  // complete the function here
+  return number / 2;
 }
 
-var result = halve(12);
+var result = halve(30);
 
 console.log(result);
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..fad05ab74 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,7 @@
 function triple(number) {
-  // complete function here
+  return number * 3
 }
 
-var result = triple(12);
+var result = triple(50);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..a4eed9d76 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,6 +1,7 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(num1, num2) {
   // Calculate the result of the function and return it
+  return num1 * num2;
 }
 
 // Assign the result of calling the function the variable `result`
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..94b832b22 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,4 +1,6 @@
-// Declare your function first
+function divide(num1, num2){
+    return num1 / num2;
+}
 
 var result = divide(3, 4);
 
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..87712af9a 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,4 +1,6 @@
-// Write your function here
+function createGreeting(name){
+    return  "Hello, my name is " + name;
+}
 
 var greeting = createGreeting("Daniel");
 
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..ae56655fc 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,7 @@
-// Declare your function first
+function add(num1, num2){
+    return num1 + num2;
+}
 
-// Call the function and assign to a variable `sum`
+var sum = add(13, 124);
 
 console.log(sum);
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..91413650d 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,4 +1,6 @@
-// Declare your function here
+function createLongGreeting(name, num1){
+    return "Hello, my name is " + name + " and I'm " + num1 + " years old";
+}
 
 const greeting = createLongGreeting("Daniel", 30);
 
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..04532b9db 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -3,3 +3,37 @@ var mentor2 = "Irina";
 var mentor3 = "Mimi";
 var mentor4 = "Rob";
 var mentor5 = "Yohannes";
+
+
+var mentor1 = "Daniel";
+var mentor2 = "Irina";
+var mentor3 = "Mimi";
+var mentor4 = "Rob";
+var mentor5 = "Yohannes";
+
+function capitalize(name) {
+    return name.toUpperCase();
+}
+// var result = capitalize(mentor1);
+// console.log(result);
+var shoutyMessage = "hello"
+
+function greeting(string){
+ return string.toUpperCase();
+ 
+}
+// var result2 = greeting(shoutyMessage);
+
+// console.log(result2);
+
+function shoutyGreeting(name, string){
+  return  greeting(string) + " " + capitalize(name);
+}
+
+console.log(shoutyGreeting(mentor1, shoutyMessage));
+console.log(shoutyGreeting(mentor2, shoutyMessage));
+console.log(shoutyGreeting(mentor3, shoutyMessage));
+console.log(shoutyGreeting(mentor4, shoutyMessage));
+console.log(shoutyGreeting(mentor5, shoutyMessage));
+
+
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..eb856e749 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,16 +1,17 @@
 // There are syntax errors in this code - can you fix it to pass the tests?
 
-function addNumbers(a b c) {
+function addNumbers(a, b, c) {
   return a + b + c;
 }
 
-function introduceMe(name, age)
-  return "Hello, my name is " + name "and I am " age + "years old";
-
+function introduceMe(name, age) {
+  return "Hello, my name is " + name + " and I am " + age + " years old";
+  
+}
 function getTotal(a, b) {
-  total = a ++ b;
+  total = a + b;
 
-  return "The total is total";
+  return "The total is " + total;
 }
 
 /* 
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 9cca7603b..eeb285c2c 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,18 +1,19 @@
 // The syntax for this function is valid but it has an error, find it and fix it.
 
 function trimWord(word) {
-  return wordtrim();
+  return word.trim();
 }
 
 function getStringLength(word) {
-  return "word".length();
+  return word.length;
 }
 
 function multiply(a, b, c) {
-  a * b * c;
-  return;
+  return a * b * c;
+  
 }
 
+
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index 5a953ba60..61dcc9b24 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,18 +1,19 @@
 // Add comments to explain what this function does. You're meant to use Google!
 function getRandomNumber() {
-  return Math.random() * 10;
+  return Math.random() * 10;  // it returns a random number that can be anywhere between 0 and 1. The 0 is included and 1 is excluded.
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
 function combine2Words(word1, word2) {
   return word1.concat(word2);
+  // concatenation used inside a function is used to combine words
 }
 
 function concatenate(firstWord, secondWord, thirdWord) {
-  // Write the body of this function to concatenate three words together.
-  // Look at the test case below to understand what this function is expected to return.
+ return firstWord.concat(" ", secondWord, " ", thirdWord);
 }
 
+
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index ba77c7ae2..ea45f6d72 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,10 @@
   Sales tax is 20% of the price of the product.
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(num){
+  let salesTax = num * 0.2 + num;
+   return salesTax;
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,7 +20,12 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(num) {
+  let salesTax = num * 0.2 + num;
+  return "£" + salesTax.toFixed(2);
+}
+var result2 = addTaxAndFormatCurrency(15);
+console.log(result2);
 
 /* 
 ===================================================
diff --git a/package.json b/package.json
index 93e0861e3..9e7f2ffeb 100644
--- a/package.json
+++ b/package.json
@@ -14,15 +14,21 @@
     "url": "https://github.com/CodeYourFuture/JavaScript-Core-1-Coursework-Week1/issues"
   },
   "jest": {
-    "setupFilesAfterEnv": ["jest-extended"],
+    "setupFilesAfterEnv": [
+      "jest-extended"
+    ],
     "projects": [
       {
         "displayName": "mandatory",
-        "testMatch": ["<rootDir>/mandatory/*.js"]
+        "testMatch": [
+          "<rootDir>/mandatory/*.js"
+        ]
       },
       {
         "displayName": "extra",
-        "testMatch": ["<rootDir>/extra/*.js"]
+        "testMatch": [
+          "<rootDir>/extra/*.js"
+        ]
       }
     ]
   },